car will not start power going to it if we short it out it will start? on 2003 Buick Rendezvous

as well back up lights will not work just changed the motor

Asked by for the 2003 Buick Rendezvous
Check the shifter/park neutral switch to see if out of adjustment from engine swap. Turn key to start position and move shifter back and forth.
Try to crank in neutral as well, holding key to start position and moving shifter. BRAKES APPLIED!
we tried that there is no safty neutral switch on the tranny I was wondering if maybe I have to get it re programed if there is a chip in the key. to the car or if its out of the van we took motor from.